Improvement in fire-proof safes



UNITED STATES PATENT OFFICE.

EBENEZER D. DRAPER, OF HOPEDALE, AND EDWARD W. GLOVER, OF

MEDFORD, MASSACHUSETTS.

IMPROVEMENT IN FIRE-PROOF SAFES.

Speciiication forming part of Letters Patent No. 72,176, dated December17, 1867.

` To all whom it may concern:

Be it known that we, EBENEZER D. DRAPER, of Hopedale, in the county ofWorcester, and EDWARD W. GLovER, of Medford, in the county of Middlesex,and State of Massachusetts, have invented a new and useful Improvementin Water Gases or Vessels for Fire-Proof Safes and we do hereby declarethe same to be fully described in the following specification andrepresented inthe accompanyin g drawing, which is a longitudinal sectionof a water-case provided with our invention.

In such drawing, A denotes the watercase, made in the ordinary manner,and with a tube, a, extending within it from its top, b, and openingthrough such top, the tube also being open at its lower end.

For sealing the mouth or upper end of the tube, we make use of ametallic meniscus, or -concavoconvex plate or cap, c, having a diametergreater than that of the mouth; and this meniscus we fasten in place bysoldering it to the plate b by a fusible-metal solder, d, which willmelt at a temperature below 212O Fahrenheit. This solder may be composedof bismuth, tin, and lead, in the proportions, by weight, of eight partsof the bismuth, three parts of the tin, and ve parts of the lead, thethree metals being fused together; or it may be composed of cadmium, oneto two parts; tin, two parts; lead, 4four parts; and bismuth, seven oreight parts, these metals being fused together.

By having the cap o dome-shaped, and to extend beyond the mouth of thetube a, (it being customary to make the cap of a diameter about doublethat of said mouth,) we are enabled to obtain alarge and extendedsurface over the mouth for the steam to act against in order to forceoff the cap. By making the cap concave on its lower side, the solderwill only adhere to it at or near its edge in contact with the plate b.

The water-cases, `partially filled with water,

are for use between the walls of or within a fire-proof safe, theirobject being to retain water therein, in order that when the safe may beexposed to a fire, such water may be converted into steam, and in suchstate be discharged into the chamber of the safe, and thereby preventcombustion or burning of the books, papers, or other contents of thesafe.

Our invention or improvement consists in the application of the cap c tothe mouth of the case by means of a metallic solder, d, which will meltat a temperature below that of boiling water. In other words, we sealthe mouth by a fusible metal which, at a temperature less than that ofboiling water, will melt and allow the escape of steam from the case,and in connection therewith we use a metallic concave cap, larger indiameter than the hole, such being for the purpose set forth. We do not,however, confine our invention to this special form of cap, as a simpledisk will sufiice, although not so good.

So long as the metallic sealing may remain solid, the case will behermetically sealed, and the water will be preserved from evaporation.

The mouth of the case may be sealed with the fusible metal alone; but asthisis a some what difficult matter, we prefer the metal cap soldered inplace by a fusible-metal solder which will melt at a temperature belowthat of boiling water.

We do not claim the employment of solder to connect one piece of metalto another, as such solder is ordinarily made and used.

We claim- The concave cap c, in combination with the case A and thefusible-metal sealing or solder d, of the kind described, suchl capbeing arranged with the mouth of the case, in the manner as set forth.

EBENEZER D. DRAPER.

EDWARD W. GLOVER. Witnesses:

GEO. H. ANDREWS, F. P. HALE, J r.

